Re: Hurricane leslie coming north, need I be concerned?
You have received good counsel on cancelling a trip along the south side of Long Island from NYC to Montauk given the anticipated sea conditions. A wise man would follow it.
If you do chose to go eastward through Long Island Sound, you can enjoy a fine sail until you pass the Race, at which time you should anticipate swells increasing from the seaway between Montauk and Block Island as you progress into Block Island Sound. Ocean swells will affect your passage the further east you proceed and the closer you get to Block.
I own a 1967 Hinckley Bermuda 40 aft cabin yawl that I keep at Brewer Cowessett in upper west Narraganset Bay. The only time I have had green water in the cockpit was a passage west to east from Stonington, Ct to Point Judith and onward up the west passage of Narraganset Bay while a hurricane was way off shore. Block Island Sound is not protected in the same way as Long Island Sound. Similarly, once into Rhode Island Sound heading east to Cuttyhunk, and Martha's Vineyard, this is also unprotected sea which can and does become quite challenging.
Chest harnesses, safety equipment including straps and safety deck lines to clip into are not only wise, but quite important, with no crew member on deck with being strapped in. And while the anticipated route of a hurricane is a nice prediction, it is only that. Last year all transitient vessels in Great Salt Pond (west entrance) and Old Harbor (east side) of Block Island were required to leave prior to the hurricane.
So if you venture out, please plan for safety and know where you can safely weather the storm away from your home mooring/dock. 9 feet of waves at sea can be exhausting and worse. Be safe....